Strange node.js error: TypeError: Object #<Object> has no method 'on'
TypeError: Object #<Object> has no method 'on'
    at Object.<anonymous> (/Users/avishai/Downloads/anismiles-jsdom-based-screen-scraper-f0c79d3/searcher-server.js:9:10)
    at param (/Users/avishai/.node_libraries/.npm/connect/0.5.10/package/lib/connect/middleware/router.js:146:21)
    at param (/Users/avishai/.node_libraries/.npm/connect/0.5.10/package/lib/connect/middleware/router.js:157:15)
    at pass (/Users/avishai/.node_libraries/.npm/connect/0.5.10/package/lib/connect/middleware/router.js:162:10)
    at Object.router [as handle] (/Users/avishai/.node_libraries/.npm/connect/0.5.10/package/lib/connect/middleware/router.js:168:6)
    at next (/Users/avishai/.node_libraries/.npm/connect/0.5.10/package/lib/connect/index.js:218:15)
    at Server.handle (/Users/avishai/.node_libraries/.npm/connect/0.5.10/package/lib/connect/index.js:231:3)
    at Server.emit (events.js:45:17)
    at HTTPParser.onIncoming (http.js:1078:12)
    at HTTPParser.onHeadersComplete (http.js:87:31)

function books(app){
    app.get('/:query', function(req, res, next) {

        res.writeHead(200, { 'Content-Type': 'text/html' });

        var rediff = require('./searcher-rediff');
        rediff.on('on_book', function(item){
            res.write(item + "<br/>");
        });
        rediff.on('completed', function(){
            res.end();
        });
        rediff.search(escape(req.params.query));

    });
}

SyntaxError: Unexpected strict mode reserved word
    at Module._compile (module.js:369:25)
    at Object..js (module.js:380:10)
    at Module.load (module.js:306:31)
    at Function._load (module.js:272:10)
    at require (module.js:318:19)
    at Object.<anonymous> (/Users/avishai/Downloads/anismiles-jsdom-based-screen-scraper-f0c79d3/searcher.js:2:15)
    at Module._compile (module.js:374:26)
    at Object..js (module.js:380:10)
    at Module.load (module.js:306:31)
    at Function._load (module.js:272:10)

var rediff = require('./searcher-rediff').searcher;